Transmitter control system



Sept. 19, 1933. H. P; MILLER, JR

TRANSMITTER CONTROL SYSTEM Filed Jlily l, 1930 2 Sheets-Sheet R O T N E V m HERMAN R MILLER JR.

FIG. I

ATTORN EY H. P. MILLER, JR

TRANSMITTER CONTROL SYSTEM Sept. 19, 1933.

2 Sheets-Sheet ATTORNEY R O N E V N Filed July 1, 1950 HERMAN F? MILLER JR.

' BY F|G.2 7% y Patented Sept. 19, 1933 UNITED STATES PATENT OFFICE assignor to International Communications Laboratories Inc., New York, N. Y., a corporation of New York Application July 1, 1930. Serial No. 465,202

6 Claims.

My invention relates to radio transmission systems and particularly to the power supply and control members therefor.

It has for an object the provision of a complete power supply systemfor a vacuum tube type of radio transmitter, and appropriate devices for controlling the operation thereof.

Other objects are the provision of a suitable starting and stopping means adapted to cooperate with a radio transmitter set, and especially the simultaneous or independent control of a plurality of power sources.

For still other objects it has the incorporation in a radio system of a motor generator system for supplying power to the plate circuit of a vacuum tube, and a storage battery system for supplying power to the filament circuit, with automatic means for the charging of the filament circuit batteries, and control means whereby the batteries may be automatically disconnected from the charging source, connected to the filament circuit, and. the motor generator started for transmission, and for independently shutting down the generator without disconnecting the batteries from the filament circuit, as during reception.

My invention has for still other objects the provision of means for maintaining temperature equilibrium in a vacuum tube transmitter system during the receiving periods intervening between transmission periods. It has for still other objects the provision of an interlock system for preventing injury to the vacuum tube member by preventing the application and removal of voltages in an improper sequence.

In the operation of vacuum tube transmitter devices, it has been found that the maintenance of temperature equilibrium in the transmitter tube is highly desirable, especially at the higher frequencies, since a change in size of the electrodes, due to change in temperature, changes the interelectrode capacity, and accordingly changes the generation frequency by small amounts; which, however, are sufiicient to require re-adjustment of a receiver responsive to such signals as the tube approaches temperature equilibrium from a cold condition. This uniform temperature is most conveniently obtained by keeping the filament lighted during nontransmitting periods, thereby permitting the heat of the filament to maintain substantially the same temperature equilibrium as is obtained during transmission periods. It is, however, usually desirable that the plate generator, the driving motor and any other rotating members be shut down during receiving periods, because of the unavoidable production by them of noises in the receiver due to oscillations and impulses from the commutators and other vibrations generally. In view of the fact also that the plate generator and batteries are often not disposed at the same point as the transmitter panel, it is also desirable that a simple system of remote control be provided, adapted to the performance of these various functions.

My invention provides a control system by means of which, through the movement of a single button or similar control member, the batteries may be taken off charge, connected to the filament circuit, and the plate generator started; and then, by the pressing of a second button, the plate generator may be shut down, without disconnecting the batteries from the filament and thereafter by pressing the first button the generator may be re-started; or by pressing a third button, the batteries may be disconnected from the filament, if the generator is running it also is shut down and simultaneously the batteries are replaced on charge.

This system is particularly advantageous because of the lengthened life obtainable from the oscillator tube. It has been found that when the vacuum tube is energized, the surge of current in the filament is injurious both to the filament itself and to the various mountings, and other elements, and a much greater life is obtainable from a given tube if the filament is maintained energized continuously during communication periods, instead of being de-energized during the time that messages are being received. It appears that more injury is done to the filament by re-heating it from the cold condition than is done by maintaining it hot during the ordinary period for receiving a message. My system thus substantially increases the life of the vacuum tube in a transmitter system.

Other objects and structural details of my invention will be apparent from the following description when read in connection with the accompanying drawings in which:

Figure 1 is a diagrammatic representation of circuits and apparatus of my invention embodying a remote control system with plate generator and filament batteries, and

Fig. 2 is a similar embodiment including in addition both filament batteries and a filament generator.

In Fig. 1, the radio transmitter system 1, which may be mounted within a cabinet or container 110 connected in series.

2 is shown as comprising a vacuum tube 3 and appropriate oscillatory circuits 4, the plate circuit being coupled to the antenna. Suitable keying and interrupting means are also desirably provided as shown, together with appropriate safety and control members.

A motor generator set 5 is provided, desirably comprising a motor 6 and a high voltage generator '7 operated by current obtained from a suitable source through the mains 8, and-a power switch 9, which is desirably positioned upon the radio transmitter panel as indicated.

An appropriate filament battery system 11 with batteries 12 is also provided, associated with an appropriate control system 14. A motor starting panel 15 is also provided, and in addition a control station 16 comprising a plurality of push buttons or switches. The control station may be a single set of push buttons in an appropriate single or multiple support, or a plurality of sets may be provided and positioned at different points from which control is desiredsuch for instance as at'the key desk, at the generator room and at the transmitter panel. The embodiment disclosed, however, presents but a single set of control buttons; the changes necessary for the provision of a second set will be obvious to one skilled in the art.

The system presented in this embodiment is designed to operate upon direct current such as from a ships supply to which the mains 8 are connected.

In the stand-by condition, with the batteries less than fully charged, current fiows from the mains 8 through the lead wires 17, the regulating resistance 18 and the ammeter 19 to the batteries 12 by way of the contacts 21 and the connected wires in a path which will be obvious, the two sections of the battery 12 being thereby The charge limiting meter 22 is also provided in the battery circuit. The contacts 21 are held closed by a relay coil 23 supplied with holding current through a circuit which will be later described.

Mains 24 are also provided, connected to the mains 8 and leading to the motor starting panel 15 and the motor 6 as shown.

When the operator desires to transmit, he presses the button 25 in the control station 16, whereupon a circuit is completed from one of the mains 24 through the wire 26, the button 25 and its associated contacts, the closed buttons 27 and 28, the wire 29, and the coil 31 to the other of mains 24. Energization of the coil 31 closes the associated power contacts as shown, and applies power to the motor 6 through the wires 32 and 33 as indicated, whereupon the motor comes up to speed, driving the high voltage generator 7 which is connected to the plate circuit of the transmitter. Simultaneously upon the pressing of button 25, current passes through the wire 34, and the contacts 35 to the coil 36 of the filament circuit relay, the wire 37 leading to one of the leads 17 and the power supply circuit serving to complete the circuit. Energization of the coil 36 attracts the armature and by the indicated system of levers and weights throws the associated contacts 38 to the closed position, where they are held by gravity, and

' simultaneously opens the contacts 35 breaking the circuit to the coil 36, and preparing another circuit by closing contacts 39.

The relay just described is outlined as one in which an unstable weight holds the contacts either open or closed, actuation of the relay coil serving to pull the weight upward in an arc which carries it from one position to the other, and simultaneously breaks the contact to the coil. It is of course obvious that other types of relays may be used by appropriate changes in the circuits.

The movement of button 25 simultaneously opens the circuit between the lead 26, which is connected to one of the mains 24, and the lead 41 which supplies current through contacts 42 to the coil 23 of the charging relay. The circuit of the coil 23 is completed by a lead 43, through the contacts of the charge controlling meter 22 to the lead 37, which in turn is connected to the lead 17 and the other of the mains 24. The opening of this circuit deenergizes the relay 23, the contacts 21 are opened, and the battery is thus taken off charge. At the same time the energization of the relay 36 opens the contacts 42, so that when the button 25 is released, the circuit through the coil 23 is not restored, and contacts 21 remain open.

The battery is thus connected to the filament circuit (and incidentally to the field of the high voltage generator 7 as shown) with its sections in parallel, and as the motor and high voltage generator are brought up to speed, current is supplied to both the filament and plate circuits, and the transmitter prepared for operation. At the completion of the transmission of a message, the operator may desire to listen for an answer and may desire to shut down the high voltage generator to avoid any interference produced thereby. He accordingly presses the button 27, which interrupts a holding circuit established by way of lead 44 as shown, to'the coil 31, permitting the armature to drop out and open the motor circuit contacts, thus shutting down the motor, as desired. It may be noted, however, that the coil 36 is not energized and accordingly no change is made in the filament or battery circuits, thus maintaining the energization of the filament. Upon the completion of reception button 25 may be pressed again, whereupon the same circuit is made as before to the coil 31, and the motor starter actuated to bring the motor up to speed and the plate generator up to voltage, whereupon transmission may be resumed.

An incidental feature in the system of Fig. 1

lies in the fact that the chopper shown in con-' nection with the vacuum tube keying system is supplied with current only when the motor 6 is operating. This feature is obtained by connecting the chopper motor in parallel with the motor starter contacts by leads as shown.

A plate circuit contactor is also included in the system, with the coil energized from the same contacts in the motor starter 15. This relay operates to disconnect the field of the gen erator 7 immediately when the motor starter 15 is open-circuited, and also to disconnect the plate lead, thereby destroying the high voltage generator field flux, and opening the plate lead to insure the removal of all plate power from the vacuum tube 3. Both of these members being thus supplied with current through the motor starter, they are automatically actuated by the starting and stopping buttons in the push button system 16.

When it is desired to shut down the whole of the power supply, button 28 may be pressed which opens the holding circuit to the coil 31 in the same way as does the pressing of button 27,v and also by closing the bottom contacts,

.63 and filament generator 51.

supplies current through the lead 45 to the coil 36, restoring it to its previous position, opening the contacts 38 and 39 and closing the contacts 35 and 42. The opening of the contacts 38 disconnects the batteries from the filament circuit, and the opening of the circuit to the coil 31 causes the motor starter to drop out and shut down the plate supply motor-generatorL Simultaneously, the contact 42 is closed and the circuit reestablished'through the button 25 and lead 41 from the lead 26 and mains 24, to the coil 23, energizing the coil 23 which thereupon closes the contacts 21, returning the batteries 12 to charge.

The charging then continues until a full charge is obtained, whereupon the charge control meter 22 operates to open the circuit of the coil 23 and thereby open the contacts 21, taking the batteries off charge.

Under certain conditions it is desirable that both'a low voltage generator and batteries be provided for energizing-the filament of the transmitter, with means as before described for disconnecting the plate power supply without disconnecting the filament power supply. A system adapted to'meet this requirement is shown in Fig. 2.

In Fig. 2 certain similar elements are provided as in the embodiment of Fig. 1, and indicated by the same numbers, including a radio transmitter system 1 mounted within a cabinet 2 and including a vacuum tube 3 and .an oscillatory circuit system 4. A motor generator set 5 is also provided including a driving motor 6, a high voltage generator 7 and a low voltage generator 51 Power supply for the motor 6 is obtained through mains 8 and a main switch 9, as before. Bateries 12 are also provided, and a motor starting device 15 as before. The motor starting device 15 is operated by contacts in a push button control member 52, which however may have but two buttons, one for start, and one for stop, as distinguished from the control member 16 of the previous embodiment. An auxiliary filament circuit holding switch member 53 is also provided which is desirably positioned adjacent to the push button member 51, for the filament control. A battery control and charging system 54 is also provided containing a battery charge meter 55 and a charging relay 56. Double-throw manuallyoperated change-over switches-57 and 58 are also provided for connecting the batteries either to .the charging mains 17 or to the filament circuits of the triode 3, and connecting either the batteries or the filament generator to the filament circuits.

In the stand-by condition, the switch 58 is desirably thrown to the right, therebyconnecting the batteries 12 in series to the mains 17, which are appropriately connected through the charging control meter 55 and relay 56 to a direct current power supply. Current then flows .to the batteries until they are fully charged as indicated by the meter 55 which thereupon opens the charging circuit by means of the relay 56. The charge rate is controlled by the rheostat 59'and indicated by the ammeter 61.

If the batteries are on charge, and it is desired to operate the transmitter 1 without using the batteries, the switch 57 may also be thrown to the right, thereby connecing the filament circuit mains 62 to the filament generator mains Button '64 may then be pressed, whereupon current fiows from one of the mains 8 by way of the coil 31 in the motor starting panel 15, the contacts 65 of the overload relay 66, the lead 67 to the switch 57, then to the switch 58, the lead 68, the button 69, the lead 71, the button 64 and the lead 72 to circuits in the starting box 15 leading by way of the thermal overload relay 66 to the other of the mains 8. The coil 31 then closes the starter contacts, energizing the motor 6 and bringing the generators 7 and 51 up to speed to provide the power supplies for the transmitter 1, whereupon signaling may be conducted. After the button 64 is released, the circuit of coil 31 remains closed through a holding circuit which includes the contacts 65, lead 67, switches 57 and 58, lead 68, button 69, lead 71, lead 86 and the motor starting contacts as shown to the second of the mains 8. In this sequence of operations, the switch 53 doesnot function, and no provision is made for maintaining the filament excitation independently of the plate excitation, although it is of course obvious that such could be done by the interposing of an appropriate switching means in the circuit of the generator 7. portant, aside from the improved tube life, since not much quietness in the receiver is gained by shutting down the plate excitation only to the tube 3 when the motor 6 and generator 51 are running.

At the end of the signaling operations, the button 69 may be pressed, which operation opens the holding circuits to the coil 31, allowing the motor-starter contacts to open, and shutting down the motor generator set, to deenergize the transmitter.

When, however, the batteries 12 are sufiiciently charged and it is desired to utilize them for filament excitation during transmission, the switch 58 may be thrown to the left, thereby disconnecting the batteries 12 from the mains 17 and the charging system, and connecting them in parallel to contacts in the switch 57 as indicated. The switch 57 may also be thrown to the left thereby disconnecting the filament leads 62 from the mains 63 and the filament gener..- tor 51 and connecting them to the batteries 12.

The motor generator set 5 may be started as before by pressing the button 64, whereupon current fiows from one of the mains 8, by way of the coil 31, the contact 65, the lead 67, the switches 57 and 58, the lead 68, the button 69, the lead 71, the button 64, the lead 72, the circuits in the starter 15, and the over-load relay 66 to the other of the mains 8. Current in the coil 31 closes the motor starting contacts, to energize the motor 6 and bring the unit up to speed. Simultaneously the closure of the first pair of contacts in the motor starter allows the fiow of current through the leads 85, 81, and 79, the switch 57, lead 78, the coil 76 of the filament circuit relay 74, and coil of the time delay relay 7'? in parallel, and the lead 75 to the other of the mains 8. The current in the coil 76 causes the closing of the contacts 82 and 88. The closing of contacts 82 allows current to flow from the batteries 12 through switches 58 and 57 to the filament supply mains 62 by way of the indicated circuit. The closure of the contacts 83 establishes a holding circuit through the lead 73, the switch 53, the lead 72 and the circuits shown in the motor starter to the other of the mains 8. If the switch 53 is open, the holding circuit does not function. A holding circuit for the coil 31 is also established as be- This is not, however, so im-' transmitting periods.

fore described by way of the lead 86, as shown, so that the starter contacts are held closed by current in the coil 31 after the button 64 is released. If the switch 53 is open, pressure upon the button 69 interrupts the cirouit'through coil 31, and the starting contacts open, shutting down the motor 6, and simultaneously opening the circuit through the coils '76 and '77, thus disconnecting the filament circuit from the batteries at the same time that the motor generator unit 5 is deenergized. If, however, the switch 53 is closed, the holding circuit by way of the lead '73 and the contacts 83 supplies current to the coils '76 and '77 thereby maintaining the continuity of the circuit between the filamerit and batteries and keeping the filament energized from the batteries 12 during non- When transmitting is completed, the opening of the switch 53 interrupts the holding circuit to the battery contactors, and allows them to open, thereby disconnecting the filament current supply. and shutting down the transmitter completely.

The embodiment of Fig. 2 also provides a control for the chopper motor and plate circuit relay which functions to start and stop the chopper motor simultaneously with the motor generator as in the embodiment of Fig. l, and to open-circuit the high voltage generator field and plate circuit in the same way.

Thus, the second embodiment as above described obtains results largely similar to those obtained by the first described embodiment, but with a greater flexibility of operation.

By the systems of my invention as thus described, the operator of a vacuum tube radio transmitter is enabled to control the power supply sources from any convenient point, and to start up both in proper sequence, shut down one during desired periods and shut down both when desired, and simultaneously obtain an automatic charging of the battery, as well as,

the previously mentioned objects.

While I- have shown but a limited number of embodiments of the device of my invention, it is-possible to make various other modifications from the showing above made, without departing from the spirit of the invention, and I desire therefore that only such limitations shall be imposed upon the appended claims as are stated therein, or required by the prior art.

I claim as my invention:

1. Means for energizing a vacuum tube having a plurality of electrodes such as a cathode, an anode, a grid, comprising a main current supply and auxiliary sources of current for the electrodes, said sources consisting of storage batteries for supplying heating current to the cathode and a motor generator for supplying high potential current to the anode in combination with controlling switch members, one of said members being adapted to energize a holding coil 'for connecting the main current supply to the motor of the motor generator, means controlled by said member to simultaneously connect the batteries to the cathodes, auxiliary switching means responsive to the energization of the holding coil for connecting the generator field of the motor generator to the storage batteries and simultaneously connecting the generator armature of the motor generator to the anode of the vacuum tube.

2. Means for energizing a vacuum tube having plurality of electrodes such as a cathode, an anode, a grid, comprising a main current supply and auxiliary sources of current for the electrodes, said sources consisting of storage batteries for supplying heatingcurrent to the cathode and a motor generator for supplying high potential current to the anode, in combination with controlling switch members, such as a first, a second, a third, circuits connecting the electrodes, the main current supply and the auxiliary sources of current to said controlling switch members, one of said circuits, including that connecting the main current supply to the batteries, being energized when none of the electrodes are energized, a first of said switch members being adapted to de-energize said closed circuit and subsequently by further traverse 0! said member to energize a holding coil for connecting the main current supply to the motor of the motor generator and simultaneously to energize a relay for connecting the batteries to the cathode, auxiliary switching means responsive to the energization of the holding coil for connecting the generator field of the motor generator to the storage batteries and simultaneously connecting the generator armature of the motor generator to the anode of the vacuum tube.

3. Means for energizing a vacuum tube having a plurality of electrodes such as a cathode, an anode, a grid, comprising a main current supply and auxiliary sources of current for the electrodes, said sources consisting of storage batteries for supplying heating current to the oathode and a motor generator for supplying high potential current to the anode in combination with controlling switch members, such as a first, a second, a third, circuits connecting the electrodes, the main current supply and the auxiliary sources of current to said controlling switch members, one of said circuits, including that connecting the main current supply to the batteries, being energized when none of the electrodes are energized, said second of said switch members operable subsequently to the first for de-energizing the holding coil, auxiliary switching means responsive to the de-energization of the holding coil for disconnecting the generator field of the 0 motor generator from the storage batteries and simultaneously disconnecting the generator armature of the motor generator from the anode of the vacuum tube.

4. Means for energizing a vacuum tube hav- 1 ing a plurality of electrodes such as a cathode, an anode, a grid, comprising a main current supply and auxiliary sources of current for the electrodes, said sources consisting of storage batteries for supplying heating current to the cath- 1 ode and a motor generator for supplying high potential current to the anode in combination with controlling switch members, such as a first, a second, a third, circuits connecting the electrodes, the main current supply and the auxiliary sources of current to said controlling switch members, one of said circuits, including that connecting the main current supply to the batteries, being energized when none of the electrodes are energized, said third of said switch members operable subsequently to the first for de-energizing the holding coil, auxiliary switching means responsive to the de-energization of the holding coil for disconnecting the generator field of the motor generator from the storage 1 batteries and simultaneously disconnecting the generator armature of the motor generator from the anode of the vacuum tube, and subsequently by further traverse of said third of said switch members energizing means for disconnecting 1 the batteries from the cathode and subsequently by further traverse of said means connecting the main current supply to the batteries, whereby the system is shut down and the batteries are put on charge.

5. A system for energizing a vacuum tube having a plurality of electrodes such as a cathode, an anode, a grid, comprising a main current supply and auxiliary sources of current for the electrodes, said sources comprising a low potential current source for supplying current to the cathode, a high potential generator for supplying current to the anode, said generator being driven by a motor, in combination with controlling switch members, circuits connecting the electrodes, the main current supply and the auxiliary sources of current to said controlling switch members, one of said. circuits, including that connecting the low potential current 'sourceto the cathode, being closed when none of the electrodes are energized, one of said switch'members being adapted to energize a holding coil for connecting the main cur rent supply to the motor, auxiliary switching means responsive to the energization of the holding coil for connecting the field of the high potential generator to the low potential current source and simultaneously connecting the armature of the high potential generator to the anode of the vacuum tube.

6. A system for energizing a vacuum tube having a plurality of electrodes such as a cathode, an anode, a grid, comprising a main cur rent supply and auxiliary sources of current for the electrodes, said sources comprising a low potential current source for supplying current to the cathode, a high potential generator for supplying current to the anode, said generator being driven by a motor having a holding coil, in combination with controlling switch members, such as a first, a second, circuits connecting the electrodes, the main current supply and the auxiliary sources of current to said controlling switch members, one of said circuits, including that connecting the low potential current source to the cathode, being closed when none of the electrodes are energized, the second of said switch members operable subsequently to the first for die-energizing the holding coil, auxiliary switching means responsive to the deenergization of the holding coil for disconnecting the field of the high potential generator from the low potential current source and simuitaneously disconnecting the armature of the high potential generator from the anode of the vacuum tube.

HERMAN P. MILLER, JR. 

